Multi-electrode array for a beam mode fluorescent lamp

A multi-electrode beam mode fluorescent lamp comprising:

• a light transmitting envelope enclosing a fill material which emits ultraviolet radiation upon excitation;
• a phosphor coating, which emits visible light upon absorption of ultraviolet radiation, on an inner surface of said envelope;
• a thermionic cathode having a first and a second end located within said envelope for emitting electrons, said cathode including a plurality of thermionic cathode segments connected in series;
• means for coupling AC voltage to said ends of said thermionic cathode;
• a plurality of anodes including an initial anode, at least one intermediate anode and a final anode, each of said anodes located within said envelope for accelerating electrons and alternately forming corresponding first and second pluralities of electron beams, each plurality of electron beams in response to a corresponding cycle of said AC voltage applied between said anodes and said cathode, each of said anodes being spaced apart from said cathode by a distance which is approximately less than the electron range in said fill material and having a structure which permits said electron beams to pass thereby;
• said initial anode being L-shaped and connected to said first end of said cathode and extending under a first cathode segment of said plurality;
• said final anode being L-shaped, said final anode connected to said second end of said cathode and extending opposite to said initial anode a last cathode segment of said plurality;
• said intermediate anode being Z-shaped with first and second horizontal members, each of said intermediate anodes connected at a common point to one of said series connections of said cathode segments, said first horizontal member of each of said intermediate anodes extending over one of said series connected cathode segments and said second horizontal member extending opposite to said first horizontal member;
• and
• first and second pluralities of drift regions, each drift region located within said envelope through which said first and said second pluralities electron beams drift after passing through said plurality anodes, each of said drift regions having a dimension in the direction of travel of said respective electron beam which is greater than the electron range in said fill material, so that the electrons in each of said electron beams collide with the atoms of said fill material in said respective drift region, thereby causing excitation of a substantial portion of said fill material atoms and emission of ultraviolet radiation and causing ionization of another substantial portion of said fill material atoms and emission of secondary electrons, said secondary electrons causing emission of additional ultraviolet radiation and resulting in a substantial amount of visible light;
• said electron beams in said first plurality of drift regions all in one direction and alternately said electron beams in said second plurality of drift regions all in a direction opposite to said electron beams of said first plurality of drift regions.